Cutter for suction dredgers



Jan. 5, 1932. A. w. DANIELS 1,340,025

CUTTER FOR SUCTION DREDGERS Filed March 24, 1930 4 Sheets-Sheet 1 Jar/372222, I 55 Jzfiar Wd/ZZZi A. w. DANIELS 1,840,025

CUTTER FOR SUCTION DREDGERS Filed March 24, 1930 4 Sheets-Sheet 2 [7201???1277; Jrfzzr 7734126615 3 A. w. DANIELS ,0

' CUTTER FOR SUCTiON DREDGERS Filed March 24, 1930 4 Sheets-Sheet 5 mum HIIHIHII 1- J Hi HIIIIIIIIIIIIHHH WHHH I Hlllllllllllllllllll 1932- A. w. DANIELS 1,840,025

CUTTER FOR SUCTION DREDGERS Filed March 24, 1930 4 Sheets-Sheet 4 Patented Jan. 5, 1932 UNITED STATES PATENT OFFICE ARTHUR W. DANIELS, OF CHICAGO HEIGHTS, ILLINOIS, ASSIGNOB TO AMERICAN MAN- GANESE STEEL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF MAINE CUTTER FOB SUCTION DREDGERS Application filed March 24, 1930. Serial 170. 438,286.

This invention relates to rotary cutters for suction dredgers.

More specifically, it is embodied in a rotary cutter having a plurality of bladed arms extending outwardly from a hub and so shaped as to bore into a lake or river bottom to loosen the sand or mud being dredged and to con dition it for suction through a dredging pipe located adjacent thereto, in accordance with common practice.

The invention comprises a novel construction whereby individual lips or blades may be removably attached to the arms of each cutter. The specific invention shown discloses lips or blades each having a plurality of lugs or tangs adapted to cooperate with opposite sides of the arm to which said lip is to be attached.

In order to be efiicient, these cutters must have blades that are reasonably thin edged, with the result that they are frequently chipped, dented or worn down. For that reason it is desirable that the blades be replaceable. Such blades have been provided before, but they have never been entirely satisfactory as under hard usage or upon hitting stones, they would become loosened.

An object of this invention therefore is to provide a cutter in which the blades or lips may be removed from the arms but which is stronger and more durable than such cutters heretofore known. f

An additibnal object is to provide acutter having removable blades, in which the blades are more firmly attached to the cutter.

I A further object ofthe invention is to provide on a dredging cutter, blades-Which may be replaced but which may easily be attached so fi'rmly that they will not be loosened by striking rocks or other obstructions.

Other objects of the invention will appear from the following description, drawings and claims.

In the drawings, in which like numerals are used for similar parts throughout- Figure 1 is a view of the cutter from the digging end;

Figure 2 is a side elevation of the cutter; Figures 3 and 4 are partial views of the cutter, in each of which a single arm is shown, the other arms being broken away for the sake of clarity;

Figures 5 and 6 are viewsillustrating the blades in the position to be attached to the arms of Figures 3 and 4 respectively;

Figure 7 is a view of the blade from another position; and

F i ure 8 illustrates the arm in the corre spon ing position.

The cutter preferably comprises a hub 10:

and a ring 12, between which extend a plurality of arms 14. This cutter is intended for and adapted to be mounted on the shaft of a hydraulic suction dredger adjacent to the suction nozzle in the usual way. In operation, it is pressed against the ground to loosen parts thereof and break it up sufliciently to be sucked into the nozzle by the dredging pumps. For this purpose, each of the arms 14 is provided at its front edge with a somewhat sharpened blade 16. These blades are sometimes made integral with the arms and sometimes made separate in order that they may be replaced. In the past, the separately constructed blades have sometimes caused trouble by becoming loosened upon hitting a rock or other hard obstruction.

The present invention avoids this difiiculty by providing on each blade a plurality of lugs or tangs and 21 (see Figures 5 and 7),

which are adapted to be attached to the outside and inside respectivelyof the arms 14. As clearly shown in Figure 7 these tangs are in staggered relation. The arms are preferably made of an irregular sha e to closely fit thesetangs, as best shown in igure 4, in which the sockets 24 are provided'for the outer tang and the sockets 25 are provided for the inner tang.

Adjacent each-tang on the blade 16 is a shoulder 28' which may be fitted to rest against the edge 29' of the arm if the maximum strength is desired. Likewise, the ends 32 of the tang may be fitted to rest against the shoulders 34, constituting the bottom of the tang receiving notches on the arms. Each tang and arm portion thereadjoining may be provided with one or more rivets, depending on the size of thetangs.

' The end of each blade should be reinforced as by the rib 36, as shown in Figure 6. This may be made in the form of an additional tang to contact the inside of the arm. It ma be enlarged and riveted, if desired.

bviously the number, size and shape of the tangs or blades may be altered. For example, as the greatest twisting strain on the blade is pressing from the inside out, this may be resisted by providing an inner tang extending nearly the length of the blade and having small outer tangs at either end thereof. Or there may be a single small outer tang located at the center. Also, each blade may be made in sections.

By means of this invention, an especially strong construction is provided. \Vhichever way the blade is twisted, the twist is resisted by the tangs on each side and by the rivets extending therethrough. Thus the blade cannot be twisted the least amount in either direction without shearing the rivets. This effect may be emphasized by the staggered shoulders which provide a staggered fulcrum for any twisting. Thus, if there is a tendency of the blade to be twisted downwardly, it must fulcrum about the extreme outer edge of the arm, with a consequent shearing strain on both sets of rivets. Thus the strength of all the rivets is combined, each having the advantage of considerable leverage over a blade attached merely on the outside. Likewise, when the twisted force is exerted inwardly, the fulcrum point is at the extreme inner edge of the arms sothat there is the same leverage against inward twisting. The strength is further increased due to the curved shape of the arms and the blades. The composite curvature of the arms and blades of course increases the effective leverage and strength of the rivets against the twisting or loosening of the blades.

It is to be understood that many other embodiments of the invention, including some in improved form, will be apparent and in the course of time will be devised by those skilled in the art. My invention includes all of these which come within the spirit of the following claims, construed as broadly as the prior art will permit.

I claim:

1. A rotary cutter for dredgers including a plurality of arms, each arm having a blade, each of said blades being attached to said arm by means of a plurality of staggered tangs, alternate tangs being on the inside of said arm and other alternate tangs being on the outside of said arm.

2. A cutter for dredgers including a blade support, and a blade carried thereby, one of said members having staggered tangs and the other member having staggered sockets therefor on opposite sides of said other member, and means rigidly securing-said tangs in said sockets.

3. A rotary cutter for dredgers including an arm, a blade carried thereby, one of said members having staggered tangs adapted to extend along opposite sides of the other of said members and fastened rigidly thereto.

4. A blade for a rotary cutter having tangs extending therefrom in staggered relation and adapted to be attached to an arm with the tangs on opposite sides of said arm.

5. A rotary cutter for a dredger including a rotatable arm having a curved surface and carrying a blade extending therefrom and approximately coincidinv with the curvature of said surface, and a plurality of tangs attached to one of said members and extending along opposite sides of the other of said members and spaced at remote Points along the curvature of said surface.

6. A rotary cutter for a dredger including a rotatable arm having a curved surface and carrying a blade extending therefrom and approximately coincidin with the curvature of said surface, and a pliuality of tangs attached to one of said members and extending along opposite sides of the other of sai members, two of said tangs on the concave side of said members being spaced at remote points along the curvature of said surface.

7. A rotary cutter for dredgers including a plurality of arms, each arm having a blade, each of said blades being attached to said arm by means of a plurality of staggered tangs, alternate tangs being on the inside of said arm and other alternate tangs being on the outside of said arm, the tangs on one side being offset not substantially more than the width of a tang from the tangs on the other side, and said arm having sockets forthe reception of said tan s but being formed of a continuous strip of metal connecting the walls of said sockets to one another.

8. A rotary cutter for dred ers including a plurality of arms and a blac e attached to each arm by means of tangs extending on opposite sides of said arms and attached thereto,the distance between opposite outer boundaries of said tangs being not substantially greater than twice the thickness of said tangs.

Signed at Chicago, Illinois, this eighteenth day of'March, 1930.

ARTHUR W. DANIELS. 

